Lipovitellins and the very low density lipoproteins will be isolated from eggs of hens fed normal diets and diets containing crude cottonseed oil or sources of saturated or highly unsaturated fats. Structures of the lipoproteins will be investigated by studies of lipid extractability, release of peptides and lipids by enzymatic digestion, structures of lipids and nature of fatty acids released, and structures of proteins and peptides released by various treatments. Size and shape of the lipoproteins will be studied by electron microscopy, gel chromatography, and disc electrophoresis. The influence of diet on the relative proportions of the two lipovitellins and the various very low density lipoproteins will also be determined. Similar studies will be made of the blood lipoproteins from the laying hen, the non-laying hen, and the cockerel. Lipoproteins will be isolated from eggs during embryonic development to study changes in the lipoproteins and their metabolism. Similarly lipoproteins will be isolated from fresh and stored eggs to determine changes that take place in non-fertile eggs during storage.